yeah this is not the output but it takes tu arguments here:
public function getQueryArray($params){
$query_array = array(
'post_status' => 'publish',
'post_type' => 'show-item',
'posts_per_page' => $params['number_of_items'],
'orderby' => $params['orderby'],
'order' => $params['order']
);
$field = get_field('date_de_debut');
if (!empty ($field)) {
$query_array['meta_key'] = 'date_de_debut';
$query_array['orderby'] = 'meta_value';
}
So there is probably a solution there !